In the analytical sciences it has become increasingly common-place to use instruments with automatic sampling facilitates (autosamples), e.g. with chromatographs or spectrophotometers. Such facilities usually take the form of a carousel arrangement in which vials containing samples for examination are located around the periphery of the carousel. Thus, samples may be separately presented for analysis on rotation of the carousel. Each auto-sampler is arranged to accept only one size of vial. Thus, while one autosampler is arranged to accept one size of a vial, another autosampler will only accept a different size of vial.
A typical conventional autosampler manufactured by Magnus Scientific Instrumentation Ltd. includes a turntable having openings for receiving vials which in turn house the samples which are to be analyzed. Typically, a needle is introduced into each vial, a sample removed from each vial, analyzed, the needle purged, the turntable rotated to the next vial position, the needle again inserted into the next vial, and the sampling recommences. A specific Magnus autosampler as aforesaid is identified by Model No. M7110 which has been in use and generally available to the public from at least 1981. A similar autosampler which has been available at least as early as Feb. 1983 is Model LC 241 of Dynatech Precision Sampling Corp. of Baton Rouge, LA.
A known disadvantage of such autosamplers is that it is not normally possible for a needle, probe or other extraction device to remove all of the sample from any given vial in the sampler. In some instances, due to the size of the gap between the bottom of the vial and the lower extremity of the extraction device, the amount of available sample is simply too small for withdrawal.
In cases where an adequate volume of sample is available, the existence of a gap between the bottom of the vial and the extraction device presents no problem, but many laboratories, especially those in hospitals, frequently have to accept inadequate sample volumes for examination, and difficulties may then arise.
Thus, there is a clear need to provide a low volume vial which inside is sufficiently narrow to cause displacement of the sample contents when an extraction device enters the vial, enabling small quantities to be extracted from small sample volumes. Preferably, the vial also has an external convex-shaped bottom.
Unfortunately, vials meeting these requirements have been found to be too narrow to fit into typical autosampler devices, or if not, need to be specially made for the requirement and so would prove to be very costly.